Deburring apparatus



1966 M. M. GUIBERT ETAL 3,230,669

' DEBURRING APPARATUS Original Filed March 5, 1965 2 Sheets-Sheet 1 2 .J 2 M R 0 6 E;- H w a. M mM V r 4 .k U 4 D1. A N 9 E 6 0 C E0 N VK r 6 P o 1 9 N m M WE m MW 2 a E F M w P 4 WM W 4 8 E7/- 0% WA 0M {I MM Jan. 1966 M. M. GUIBERT ETAL 3,230,669

DEBURRING APPARATUS 2 Sheets-Sheet 2 Original Filed March 5, 1965 2560/; AND aaosme SEQ/N65 2o INVENTORS.

United States Patent 3,230,669 DEBURRING APPARATUS Martin M. Guibert, Port Orchard, and Curtis S.Skinner, Jr., Renton, Wash., assignors to The Boeing Company,

Seattle, Wash., a corporation of Delaware Original application Mar. 5, 1963, Ser. No. 262,894, new

Patent No. 3,128,577, dated Apr. 14, 1964. Divided and this application July 31, 1963, Ser. No. 303,706

6 Claims. '(Cl. 51--7) This application is a division of application Serial No. 262,894 filed March 5, 1963, now Patent No. 3,128,577 granted April 14, 1964, and relates to the apparatus for surface finishing of .a workpiece. More particularly this invention relates to the apparatus for removing burrs causedby machining, generating a small radius where the burrs were, and improving the machined surface by removing cutter marks.

In the past years many attempts to devise an economical method of deburring spar details and other long, straight components have been made by machine builders and companies associate-d with the airframe industry. These methods have included deburring with chemicals, deburring in a vibrating tank of abrasive media, deburring by reciprocating the workpiece in a tank of abrasive media, deburring by electro-chemical deplating, and deburring by abrasive blasting. All of the above stated prior methods proved unsatisfactory for production except the method of reciprocating a workpiece submerged in a bed of abrasive media that was fluidized by vibration. While this method was economical and produced excellent results, the maximum workpiece length was limited by the size of the abrasive bed. Since spars utilized in the airframe industry range to a length of 55 feet, the above method of reciprocating a spar of that length in a bed of abrasive media was economically prohibited due to the length of the bed required therefor.

The instant invention overcomes the objections of each of the above stated prior deburring methods by providing an apparatus for'carrying out the same which provides the following features:

(1) A tank of abrasive media fluidized by vibration;

(2) A means of feeding the workpiece through the media;

(3) A system of retaining the media while feeding through the workpiece; and

(4) A means for reciprocating the workpiece longitudinally while it is being fed through the media.

Therefore, it is an object of this invention to provide an apparatus for deburring, descaling, or surface finishing of elements of considerable length.

It is a further object of the invention to provide an apparatus for deburring elements in a fluidized bed of abrasive media by continuous feed through and reciprocation of the elements at a predetermined rate.

Another object of the invention provides apparatus for deburring, by reciprocating action, a spar or other similar components, in a slurry of abrasive media while continuously feeding through the spar.

Other objects of the invention not specifically set forth above will become readily apparent from the accompanying description and drawings in which:

FIG. 1 is a diagrammatic view of an embodiment of the apparatus for carrying out the invention with certain elements being cut away or omitted for clarity;

FIG. 2 is a perspective view of one of the sealing means of the invention;

FIG. 3 shows in detail the drive mechanism of the FIG. 1 apparatus; and 7 FIG. 4 shows in detail an embodiment of the enertia retarder means for the feed mechanism of the FIG. 1 apparatus.

FIG. 1 shows a housing 1 having support mechanism "ice 2, said housing being divided into three compartments, the two end compartments constituting spillage oa tchatanks 3, the center compartment 4 constituting a tank for the abrasive media 5. Each of the walls of the center compartment 4 is provided with aligned sealing means 6 to permit the passage of workpiece or spar 7 therethrough, the details of sealing means 6 being described hereinafter. Each of the outer walls of compartments 3 can be provided with sealing means such as sealing means 6 ofcompartment 4 to provide additional sealing if desired. In operation abrasive media 5 completely surrounds spar 7 but has been here shown below the spar for clarity.

Powered feed rolls 8, which are in this instance Adiprene covered, are mounted on reciprocating arm mechanism 9 and feed spar 7 through housing 1, media 5 and sealing means 6 at a predetermined speed. While not shown completely, identical reciprocating arm mechanism 9 and feed rolls 8 are positioned on the opposite side of housing 1. Reciprocating arm mechanisms 9 are synchronized by interconnecting bar means 10 and driven via pitman 11 by drive motor and gearing mechanism 12, shown in detail in FIG. 3.

The lower feed rolls 8 are powered by motor and gearing mechanism 12 via chain or be'ltancl pulley means generally indicated at 13. The upper feed rolls are driven by coupling means 14, for example, universal joints connected with the drive means 13. All of the-feed rolls 8 are driven in synchronization. Positioned on each arm mechanisms 9 is feed roll pressure adjustment mechanism 15.

Bucket conveyor means 16 is operatively positioned in each of spillage catch-tanks 3 (only one conveyor being shown) to return the media 5 which has spilled through sealing means 6 to the center compartment 4. The drive (not shown) for conveyor means 16 can be powered from chain and pulley means 13 or can be driven by a separate motor if desired.

As shown in FIG. 2, sealing means 6 comprises a frame 17 for holding interleafed strips generally indicated at 18 of flexible material such as rubber and sheet metal such as aluminum. Strips 18 are adjusted to the configuration of the workpiece or spar 7 and are held in place by thumb screws 19 which are screw threaded through frame 17 to press blocks 20 against the strips 18 thus permitting the workpiece to pass through With a minimum of spillage of media 5.

The drive motor and gear mechanism 12 as shown in FIG. 3 comprises an electric motor 21 driven by any available source of power, a power train generally indicated at 22 interconnects the output shaft of motor 21 with a crank 23 which drives pitman 11 for driving reciprocating arm mechanisms 9. Power train 22 includes ring gear and pinion means 24 which powers chain and pulley means 13 for driving feed rolls 8.

FIG. 4 shows inertia retarder means for reciprocating arm mechanisms 9 to cushion the shock load at the stroke reversal point, and to assist in overcoming inertia at the start of the stroke in the opposite direction. The inertia retarder means comprises a bumper plate 25 positioned under housing 1 and rigidly attached to support mechanism 2. Interconnecting bar means 10 passes through the upper portion of bumper plate 25. Positioned on bar 10 on each side of bumper plate 25 in opposed relationship are recoil and booster spring means 26, spring means 26 being adjustably located on bar 10 by means 27 whereby the position of the spring means may be adjusted in accordance with the desired length of stroke of arm mechanisms 9.

Also shown in FIG. 4 are the vibrators to fluidize the media 5 which consist of air powered vibrators 28 attached to the bottom of the media tank (center compartfiltering ment) 4 and connected with'an air supply source by conduit means and controls as generally indicated at 29.

Fluidization of media serves the following functions:

1) It lessens the resistance to the spars passing through; 1

(2) It causes the media to move constantly, thereby presenting fresh abrasive to the workpiece on a continuous basis. This expedites metal removal and prevents the media from loading and glazing;

(3) It rotates the mass of media vertically in the tank, thereby carrying a cleaning compound and water solution from the bottom of the tank to the work area; and

(4) It aids, to a limited extent, the deburring and surface improving action of the process.

Though not shown in the instant embodiment of the: apparatus, the media 5 is supported by a sheet metal plate, located approximately 6 inches above the bottom of tank 4. The void beneath the plate and a portion of the media area in the tank is filled with a water and cleaning compound solution. The solution filled area below the plate serves the dual purposes of lessening the weight to: be vibrated by reducing the media load, and of dispersing the'vibration (induced at two spots on the tank bottom) evenly beneath the plate. The solution in the media functions for cleaning the media during deburring.

While the instant embodiment of the apparatus utilizes air powered vibrators, mechanical vibrators are also efficient for media fluidization and can be utilized on the apparatus, if desired.

While not shown, -the apparatus includes a solution andrecirculating systemfeeding into the abrasive media. g I

Also, two 'sets'offeed rolls can be mounted on each of the reciprocating arms. The rolls would be mounted in pairs with the axes at 90 degrees to facilitate grasping the workpiece by the sides, or at the top and bottom. All rolls would be driven in synchronization as in the instant embodiment.

The following example is set forth to show the advantages of the invention under actual work conditions and to'set forth its elfective range of operation:

Mediatanklength: 4 foot Workpiece length: 12 foot Constants:

(1) Media-bonded aluminum oxide triangles, Size No. 2. (2) Media weightl06 pounds/cubic foot. (3) Total media in tank at maximum depth2880 cubic inches. (4) Total workpiece and media contact area576 sq. inches. (5 Vibration-4300 cycles per minute. (6) Vibration amplitude-0.015 inch. (7) Feed roll pressure on workpiece-l84 pounds.

(8) Media pressure/square inch/ inch height- 0.0709 pound. Variables: i

(1) Media height above top of Workpiece2 to 5 /2 inches.

(2) Reciprocation65 to 130 stroke cycles/minute. 3) Stroke length-0 to 2% inches. (4) Feed rate-6 inches to 2% feet/minute.

The parts in this example were machined T section aluminum spar details. This configuration, because of the thin leg, offered a minimum contact area to the feed rolls, thus reducing the gripping capacity of the rolls due to the narrow area of the workpiece and thereby providing the most severe feed conditions of any spar type.

Tests were conducted under the various combinations possible with the conditions above. Parts were fed through singly, and with one part fastened end to end with another.

W ile the method and apparatus of the invention performed satisfactorily under all of the conditions tested, the bmt combination of variables developed was:

(1) Reciprocationl30 stroke cycles/minute.

(2) Media height above top ofworkpiece-S /2 inches.

(3) Stroke length-2 inches.-

(4) Feed rate,2% feet/minute.

Under the conditions set forth directly above the parts were completely deburred, and the design-required corner radii of 0.008 to 0.010 inch developed. The deburring rate of 2% feet/minutewas approximately five times that of manual deburring which wasqthe only prior known method of de'burring partsof considerable length.

The following are features which are incorporated into the deburring apparatus of the instant invention:

(1) Sets of synchronized feed rolls to facilitate grasping the workpiece and feeding it through the abrasive media. a

(2) A vibratory system, with variable controls for both amplitude and frequency.

(3) A solution filtering and recirculating system for cleaning the media.

(4) A media tank with the maximum length compatible with the shortest part planned for this process. The tank contains 6 inches of media below the workpiece, and 6 inches beyond the widest part planned for processing in the machine. The interior of the tank is designed to contain no square corners or pockets capable of causing media retention and packing at the entrance and exit ends.

(5) A quick-detach means of installing and removing the door seal retainers, the door seals being flush with the interior of the media tank.

(6) The media tank floated on springs or air cushions similar to conventional vibratory tubs.

(7) The feed rate variable from 2 to 15 feet per minute.

(8) The reciprocation rate variable from 65 to 300 stroke cycles per minute.

(9) Media flow under vibration in a circular lateral pattern with-no longitudinal media flow in the tank.

The instant invention has thus provided apparatus for carrying out the same which has fulfilled the vast need both in the airframe industry and in other manufacturing operations dealing with long, straight line components that require deburring, descaling, or surface finishing.

Although a particular embodiment of the apparatus for carrying out the invention has been illustrated and described,'it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention, and it is intended to cover in the appended claims all such changes and modifications that come within the true spirit and scope of the invention.

What we claim is:

1. Apparatus for surface finishing metallic parts comprising: container means for abrasive media, means for feeding a metallic part through the first mentioned means and the media therein, sealing means operatively associated with said first mentioned means to substantially retain the media therein while allowing the associated part to pass therethrough, means for reciprocating the part taining said media within said container means while allowing the part to pass therethrough. 3. Apparatus for surface finishing parts comprising contamer means for abrasive media, means for vibrating said media, means for feeding a part through said container means and abrasive media contained therein, means for reciprocating the part being fed through said media, sealing means operatively associated with said container means for substantially retaining said media therein while allowing the part to pass therethrough, and inertia retarder means for said reciprocating means to cushion the shock load during the stroke reversal period.

4. Apparatus for surface finishing parts comprising container means for abrasive media, means for vibrating said container means to produce a fluidized bed of said media, said container means having a predetermined quantity of said media to operatively embed a part passing therethrough in said fluidized media, powered feed roll means for feeding a part through said fluidized bed at a predetermined rate, means for reciprocating the part substantially longitudinally while it is being fed progressively through said fluidized media, and sealing means operatively adapted to the external contour of the transverse section of the part for substantially retaining the abrasive media within said container means while allowing the part to pass therethrough.

5. Apparatus for surface finishing parts comprising container means for abrasive media, powered vibrator means operatively connected to said container means for controllably vibrating said container means so as to produce a fluidized bed of said abrasive media, means for feeding a part through said fluidized media, means for reciprocat ing the part being fed through said fluidized media, said means for feeding being operatively connected to said reciprocating means such that the part is progressively fed through said fluidized media while it is being reciprm cated, sealing means operatvely adapted to the contour of the part for substantially retaining said media in said container means while allowing the part to pass therethrough, inertia retarder means for said reciprocating means, said inertia retarder means having recoil and booster means for cushioning the shock load during the stroke reversal period and to assist in overcoming inertia at the start of the stroke in the opposite direction.

6. Apparatus for surface finishing parts comprising a first container means for abrasive media, means for vibrating said media, means for feeding a part through said media, means for reciprocating the part being fed through said media, sealing means adaptable to the contour of the part for substantially retaining said media in said first container means while allowing the part to pass therethrough, inertia retarder means for said reciprocating means, a second container means adjacent to said first container means for a spillage catch-tank, and conveyor means operatively associated with said second container means for returning the abrasive media which has spilled through said sealing means to said first container means.

References Cited by the Examiner UNITED STATES PATENTS 1,957,508 5/ 1934 Taylor 51-7 2,316,586 4/1943 Illmer et a1 51-7 2,419,448 4/ 1947 Gordon 5118 2,531,132 11/1950 Johnson 5117 2,621,446 12/1952 Russell 51--14 2,664,676 1/1954 Clippers 51-7 2,686,991 8/1954 Powell et al 51-14 2,733,563 2/1956 Kaiser 51-281 2,883,809 4/1959 Simjian 51281 2,918,926 12/1959 Behnke et a1. 3,031,802 5/1962 Leliaert 519 LESTER M. SWINGLE, Primary Examiner. 

1. APPARATUS FOR SURFACE FINISHING METALLIC PARTS COMPRISING: CONTAINER MEANS FOR ABRASIVE MEDIA, MEANS FOR FEEDING A METALLIC PART THROUGH THE FIRST MENTIONED MEANS AND THE MEDIA THEREIN, SEALING MEANS OPERATIVELY ASSOCIATED WITH SAID FIRST MENTIONED MEANS TO SUBSTANTIALLY RETAIN THE MEDIA THEREIN WHILE ALLOWING THE ASSOCIATED PART TO PASS THERETHROUGH, MEANS FOR RECIPROCATING THE PART THAT IS FED THROUGH THE MEDIA, AND MEANS FOR VIBRATING SAID FIRST MENTIONED MEANS. 